The goal of this study is to develop and pilot test an innovative intervention "toolbox" to reduce HIV- associated sexual risk behaviors among methamphetamine using men who have sex with men (MUMSM). Our proposed study is based in San Diego, CA, the city with the third highest rates of methamphetamine use among arrestees in the country, and where methamphetamine accounts for over 50% of drug-related mentions in emergency departments. Drug users are a heterogeneous population requiring interventions tailored to meet their individual needs, yet most intervention trials have included only subsets of MUMSM. We propose to develop and pilot test an intervention that can be uniformly implemented among MUMSM who vary in terms of HIV serostatus and route of drug administration. Our specific aims are to: 1) develop a six-session intervention of theoretically-driven behavior change activities designed to decrease HIV- associated sexual risk behaviors among HIV-positive and HIV-negative, injection drug using (IDU) and non- IDU MUMSM; 2) determine the acceptability of the intervention series among MUMSM in all HIV and IDU strata; 3) determine the potential efficacy of the intervention series to decrease sexual risk behaviors; and 4) determine the cost-effectiveness of the intervention using a hypothetical range of effect sizes. To achieve these aims, focus groups and intervention pre-testing with the target population will be conducted to develop and refine the intervention. Eighty MUMSM will be enrolled in a single arm pilot study in which behavior change will be compared within participants on data collected using audio computer assisted self interviewing (ACASI) conducted at baseline and two months post-intervention. Our recruitment strategy will capitalize upon the ethnically diverse population of Hispanics and African American MUMSM in San Diego, as well as our ability to recruit MUMSM who are recent HIV seroconverters from an ongoing study of acute and early HIV infection. To our knowledge, this will be the first sexual risk reduction intervention ever studied that addresses the heterogeneous nature of MUMSM. If this pilot study shows promising results, it will provide the foundation for proposing a Phase III efficacy trial. If proven cost-effective, this intervention could fill a critical gap by providing much needed options for reducing the risk of sexual HIV transmission among MSM who use methamphetamine. [unreadable] [unreadable] [unreadable] [unreadable]